[PATCH v2 01/13] powerpc/mm: Add DEBUG_VM WARN for pmd_clear
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STALE2227d
From: Aneesh Kumar K.V <hidden>
Date: 2020-08-19 13:02:01
Also in:
linux-mm
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Revision v2 of 3 in this series.
Revisions (3)
- v2 current
- v3 [diff vs current]
- v4 [diff vs current]
With the hash page table, the kernel should not use pmd_clear for clearing huge pte entries. Add a DEBUG_VM WARN to catch the wrong usage. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/include/asm/book3s/64/pgtable.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 6de56c3b33c4..079211968987 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h@@ -868,6 +868,13 @@ static inline bool pte_ci(pte_t pte) static inline void pmd_clear(pmd_t *pmdp) { + if (IS_ENABLED(CONFIG_DEBUG_VM) && !radix_enabled()) { + /* + * Don't use this if we can possibly have a hash page table + * entry mapping this. + */ + WARN_ON((pmd_val(*pmdp) & (H_PAGE_HASHPTE | _PAGE_PTE)) == (H_PAGE_HASHPTE | _PAGE_PTE)); + } *pmdp = __pmd(0); }
@@ -916,6 +923,13 @@ static inline int pmd_bad(pmd_t pmd) static inline void pud_clear(pud_t *pudp) { + if (IS_ENABLED(CONFIG_DEBUG_VM) && !radix_enabled()) { + /* + * Don't use this if we can possibly have a hash page table + * entry mapping this. + */ + WARN_ON((pud_val(*pudp) & (H_PAGE_HASHPTE | _PAGE_PTE)) == (H_PAGE_HASHPTE | _PAGE_PTE)); + } *pudp = __pud(0); }
--
2.26.2